Peracid compositions (also referred to as peroxycarboxylic acid compositions) exhibit useful antimicrobial and bleaching activity. Conventional peroxycarboxylic acid compositions typically include short chain peroxycarboxylic acids or mixtures of short chain peroxycarboxylic acids and medium chain peroxycarboxylic acids, such as those disclosed in U.S. Pat. Nos. 5,200,189, 5,314,687, 5,409,713, 5,437,868, 5,489,434, 6,674,538, 6,010,729, 6,111,963, and 6,514,556, each of which is incorporated by reference in its entirety. Such peroxycarboxylic acid compositions usually contain significant quantities of hydrogen peroxide to afford shelf stability of the peracid product. Most often the peroxycarboxylic acid compositions are provided in equilibrium, including for example, peroxyacetic acid, acetic acid, hydrogen peroxide, and water.
Despite the improvements in stability obtained for peroxycarboxylic acid compositions having hydrogen peroxide, the oxidizing agent has detrimental effects on the antimicrobial activity of the peroxycarboxylic acid compositions. Therefore, the reduction of hydrogen peroxide content relative to the peroxycarboxylic acid content of the peracid composition is desired to provide enhancements in antimicrobial efficacy. For example, the use of catalase or enzymatic peroxide destroying agents has been reported to improve antimicrobial and sporicidal efficacy in U.S. Pat. No. 6,627,657, which is incorporated by reference in its entirety. The use of enzymes to selectively but destructively reduce the level of hydrogen peroxide in dilute use solutions of peracetic acid has provided improvements in antimicrobial efficacy of peracid compositions at a point of use. However, improvements to such methods are desired. Further, improvements to such methods that are non-enzymatic, non-destructive and allow the treatment of concentrated peroxycarboxylic acid compositions are desired. Still further, methods that create usable, stable materials from the removed hydrogen peroxide are desired.
Accordingly, it is an objective of the invention to develop non-enzymatic methods for reducing hydrogen peroxide content of peroxycarboxylic acid compositions.
According to a further object of the invention, it is desired develop improved antimicrobial activity peroxycarboxylic acid compositions, namely compositions with improved efficacy against bacterial spores and fungi and other microorganisms with resistance to germicidal materials.
A still further object of the invention is to develop methods of reducing hydrogen peroxide content of peroxycarboxylic acid compositions while simultaneously providing compounds of coordinated urea (or other active oxygen coordinating compound) and hydrogen peroxide for use as bleaching agents.